Internal combustion hammer



April 9, 1935. J, A MOULD 1,997,072

INTERNAL COMBUSTION HAMMER Filed July l1, 1931 5 Sheets-Sheet 1 Fmi.

April 9, 1935. LA MOULD 1,997,072

INTERNAL COMBUSTI ON HAMMER Filed July ll, 1931 5 Sheets-shew, 2

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INTERNAL COMBU ST I ON HAMMER Filed July 11 1951 3 sheets-sheet 3 EEE I O 0 O ,2Q Z5 o Z5 o Snventor Gttornegs Patented Apr. 9, 1935 INTERNAL ICOMBUSTION HAMLIER James A. Mould, Milwaukee, Wis., assigner to Gas Tool Patents Corporation,l Chicago, Ill., a corporation of Delaware Application July 11,`1931, serial No. 550,188

16 Claims.

This invention relates to improvements in internal combustion hammers.

The present invention seeks to provide many refinements for internal combustion hammers of the type shown in Patent 1,782,740 dated November 25, 1930, and representing the results of much experimental research.

It is my primary Object to provide a novel organization of the casting parts and tie rods of a device of this character productive of important results from a practical standpoint.

More particularly stated', I propose to eliminate gaskets and joints from the firing chamber and the oil chamber; to make it possible to cast the anvil housing of steel and the cylinder of iron; to confine the cast iron parts between cast steel heads thereby providing adequate anchorage for the tension bolts; to make the device adaptable for exhaust from the side instead of rear, and to permit of reversing the exhaust to either the left or the right side of the cylinder as viewed in Figure 1; and finally, to achieve a very important degree of protection of the fuel tank from heat; allof the foregoing results being accomplished by a specific location of the joints between parts of the general organization of the tool.

I further seek by the present invention to dis'-`y pose the tension member which holds the parts together in such a manner that these members may take the strain of prying, and permit a better disposition of spark plug and timer7 mechanism than has heretofore been possible.

Other objects will be apparent from the disclosure.

In the drawings:vr

Figure 1 is a vertical axial section through a device embodying the invention.

Figure 2 is a plan` view of the device.

Figure3 is a. side elevation from a viewpoint ninety degrees removed from that ofv Fig. 1.

Figure 4 is an enlarged detail of the fuel tank connection in cross section.

Figure 5 is a bottom view of the apparatus.

Figure 6 is a side elevation similar to Figure 3, but showing the lower part adjusted 180 from its usual position.

Like parts are identified by the same reference characters throughout the several views.

The cylinder 6 in which piston 1 reciprocates, is an integral part of the casting which may include a flanged jacket 8 and which contains a sub-piston compression chamber 9. The piston carries a hammer I0 and is supported by comi pression springs II and I2 which are preferably (Cl. 12S-7) constructed in accordance with the disclosureof my Patent 1,782,740 and my co-pending application 550,186 filed July 11,

1931 as a continuation in part of No. 227,656 iiled October 2l, 1927. A heavier spring I2 seats within a second casting I5 which is shouldered at I6 to comprise a closure for compression chamber 9. The use of a gasket at I1 between the cylinder casting and the lower unit I5 will be noted.

The cylinder casting is preferably made of are provided at 2| for the anvil, which will be noted to have a spring guide extension 22 about which spring I2 seats directly on the anvil. Fig. I

1 illustrates the tool as it appears when it is under pressure against the work, and supportsthe anvil clear of the guide 20. When the tool is free of the work, the shock of the impact ci the hammer I0 upon anvil I8 is communicated to the guide member 28 and absorbed in very heavy springs used at 24 (Fig. 3).

The parts are maintained tension rods 25 headed at in assembly by heavy their lower ends to provide seats for the compression springs 24 and extending through guide member 20, lower unit I5, and notches in the radiating anges of jacket casting 8 to a steel ring 26 engaged about a reduced neck portion 21 of casting 8. Nuts upon the rods are' tightened upon the ring 26 to maintain the parts in proper engagement, and it will be noted that the cast iron casting comprising cylinder 6 and jacket 8 is clamped between the steel ring 26 and the lower unit I5 without directly receiving any strains incident to the action of the tension rods 25.

It is important to note that the rods 25 arev disposed at the front and -rear of the tool in `preference to disposition at the sides thereof.

It is found that -workmen use the tool for yprying, and that a disposition of these rods at the front and rear better enable them to withstand the strains incident to the prying manipulation of the tool as a whole. Furthermore, the

disposition of the rods at front and rear makesv it possible to locate the exhaust pipe at 28 on one side of the tool, and the spark plug 29 and timer 30 at the other side of the tool directly beneath one of the handles 3| ring `26 is provided.

with which the steel The wiring to the spark plug and timer is conveniently brought in through one of the tubular ndle members, as clearly shown in Fig. 1, and thus leads directly to the plug. It is far more protected by this organization of the parts than it would be if the location of the tension rods or bolts 25 required some other disposition of the spark plug and timer.

The timer comprises a cam follower 33 acted on by a cam integral with piston 1 and held thereto by a compression spring as shown in Fig. 1. It is found that the cam surface on the piston should have a gradual incline as otherwise the cam follower will be projected with such force as to cause breakage and require an excessively heavy spring. l

The moving contact of the timer may be mounted directly on cam follower 33, but unless this contact is yieldingly mounted it is necessary to yieldingly mount the relatively fixed contact 34. It has been found exceptionally satisfactory to place the relatively fixed contact on a. spring finger which is seated normally on a stop 30, limiting its movement toward the moving contact. The wiring lead is connected with the spring finger.

Reference has already been made to the dis- 1- position of the exhaust pipe 28. It is very important to the` successful and comfortable use of the tool that it should be located as shown and arranged to discharge in a direction diagonally downward and to the left from the viewpoint of Fig. 3. The operator of a tool of this type ordinarily has a, helper who works at the side of the tool remote from a person viewing the tool as in Fig. 3. If the exhaust were at the front of the tool (at the left in Fig. 3) or at the far side, it would burn the helper. If it were at the right in Fig. 3 it would burn the operator. If it were positioned as shown, but directed straight downwardly, it would heat the fuel tank. The particular relation of 'the tie rods, fuel tank and exhaust discharge pipe 28 was only developed after extensive experimentation.

As shown in the drawings, the cylinder 6, timer, exhaust 28, closure l5, and tank, are arranged in a given relation to meet the requirements previously mentioned. However, it will be observed that the cylinder may be assembled relative to the closure so that the timer and exhaust will be positioned on the sides of the device, as a whole, opposite that illustrated in Figure 3. As previously stated, the helper is generally stationed on the right side of the device as viewed in Figure 5, but there are occasions when the helper must be stationed on the left side of the device, as seen in Figure 5. To meet these conditions the cylinder and closure are relatively rotatable, as aforesaid.

Figure 6 shows the relationship of the cylinder, closure, tank, timer, and exhaust, when they have been adjusted 186 from their usual position.

'I'he fuel tank 35 is locatell below the flanges which radiate the heat developed by combustion in the cylinder. It extends partially about the lower unit, and although it will be observed to extend above the joint packed by gasket I1 between the cylinder casting and the lower unit I5, it is not connected with the cylinder casting directly, but is wholly supported by a boss 36 on the lower unit which is shouldered at 31 to engage as shown in Fig. 3. This arrangement protects the fuel tank 'from heat which, in previous designs, has sometimes occasioned evaporation of fuel from the tank. Gasket `I1, and even a direct metal joint between the parts, has proven to be a very effective means of interrupting conductivity, and is so advantageous in this regard as to prevent heat from reaching the fuel tank in sufficient quantities to cause evaporation.

It has been found that the bolts 65 used to hold the fuel tank 35 to the supporting boss 36 should be vertically spaced rather than horizontally spaced in order to resist vibration. As shown in Fig. 3, the bolts 65 pass through compression members 66 which sustain the pressure of the heads 61 of the bolts 65. The heads 61 are countersunk in recesses 68 in the fuel tank 35 for the protection of the operator, whose clothes and person would be lacerated by the movement of the bolts 65 in the use of the tool if it were not for this provision.

Air passes downwardly through inlet duct 38 in the fuel tank unit 35 to a carbureting tting 39 bolted to the bottom of the fuel tank unit and including an air passage 4U, a valve seat at 4|, a second valve seat at 42, and check valves 43. and 44 c'o-operating with the respective seats. Seat 42 for needle valve 44 is situated in the path of ilow of fuel from the bottom of the tank 35 through duct 45 to the valve seat 4I, the arrangement being such that the fuel is controlled as to amount by the needle valve, and as to flow by the check valve 43 incident to its control of air movement. When the piston 1 moves upwardly in cylinder 6, the resulting depression in the sub-piston space 9 draws air through manifold 38 and duct 40 at valve 43, where the air is carbureted, and thence through port 41 in the fuel tank, into a complementary port 48 in boss 36.

The mixture thus admitted to the sub-piston compression space 9 is compressed during the downward movement of piston 1 and, instead of being transferred through the usual transfer passage in the cylinder wall, it passes upwardly through a duct 49 in piston 1 and thence transversely through one or more ducts 50 in the head of the piston to a by-pass notch 5I in the cylinder wall, whence the mixture issues 'into the cylinder as soon as the top of the piston clears the top of the notch. This path of travel of the mixture further cools the lower unit by not only reducing the mass of the piston head, but by conducting through the piston head the evaporation-cooled mixture on its way to the cylinder.

The component parts of the structure disclosed, other than the general organization to which the statement of objects is directed, will be covered by companion applications for patent, numbered respectively 550,186 and 550,187, and'both filed July 11, 1931 and hence are not claimed here. In the present case I claim as my invention: l

1. In an internal combustion hammer, the combination with a cylinder having a neck extension, of a. closure member for the lower end of the cylinder, a handle ring encircling said neck extension, tension rods connecting said handle ring and closure member and provided with means for maintaining them in compression upon the cylinder, handles carried by said ring intermediate said tension rods, and a spark plug directly beneath one of said handles in the cylinder and provided with electrical connections extending through said last mentioned handle.

2. In an internal combustion tool, the combination with a combustion cylinder, a closure unit for the lower end thereof, said unit being reversibly mounted on and removable from said cylinder, and a piston reciprocable in the cylinder, of handles connected with the cylinder for manipulation of the tool, and a fuel tank applied to said closure unit in a position out of contact with the cylinder and presenting a substantially smooth surface to the operator, and bolts connecting said fuel tank with said Iclosure unit and having their heads countersunk in said surface.

3. In an internal combustion tool, the combination with a cylinder unit, a closure unit -reversibly mounted on and removable from said cylinder unit, handles projecting laterally from the tool, and a piston reciprocable in the cylinder unit, of an exhaust fitting connected with the cylinder unit at the side thereof beneath one of said handles and arranged to direct its discharge forwardly, and a fuel tank secured to the closure u-nit.

4. In an internal combustion tool, the combinationwith a combustion cylinder unit, a closure unit reversibly mounted onand removable from said cylinder unit, handles projecting laterally from the tool, and a piston reciprocable in the cylinder unit, of an exhaust fitting connected with the cylinder unit at the side thereof beneath one of said handles and arranged to direct its discharge forwardly, tie rods extending longi- "secured to and extending across the rear of the closure unit.

5. In an internal combustion hammer, the combination with a cylinder unit providing a combustion chamber, of a sub-piston compression space, a closure unit providing an anvil guide, an anvil mounted in said closure unit, a piston reciprocable in the cylinder unit and carrying a hammer arranged for impact on said anvil in the reciprocation of the piston, said anvil unit providing an inlet port and said cylinder unit providing an exhaust port and a transfer passage controlled by said piston and leading thereabout from said compression space to said combustion chamber, a clamping member provided with laterally projecting handles and applied to said cylinder unit, tie rods from said clamping member extending longitudinally of said units and maintaining their connection, said tie rods being disposed at the front and rear of said units with Said exhaust port between them, and a charge forming device applied to said closure unit in a position to deliver its charge to the intake port therein, said cylinder unit having a fitting applied to its exhaust port and having its discharge opening downwardly directed in a direction inclined away from said charge forming device.

6. In an internal combustion hammer, the combination with a cylinder unit providing a combustion chamber, of a sub-'piston compression space, a closure unit providing an anvil guide, an anvil mounted in said closure unit, a piston reciprocable in the cylinder unit and carrying a hammer arranged for impact on said anvil in the reciprocation of the piston, said anvil unit providing an inlet port and said cylinder unit providing an exhaust port, and a transfer passage controlled by said piston, a clamping member provided with laterally projecting handles and applied to 'said cylinder unit, tie rods from said clamping member extending longitudinally of said units and maintaining their connection, said tie rods being disposed at the front and rear of said units with said exhaust port between them, and a charge forming device applied to said closure unit in a position to 'deliver its charge to the intake port therein, said cylinder unit having a tting applied to its exhaust port and having its discharge opening downwardly directed in a direction inclined away from said charge forming device, together with a timer including a part operated by the piston and disposed oppositely to said exhaust tting.

'7. 'I'he combination of a combustion cylinder, a. piston reciprocable therein, a lower unit reversibly mounted on the lower end of the cylinder and removable therefrom, means for thermally insulating the unit from the cylinder, a spring confined in said unit and supporting the piston, a charge forming device supported by and communicating with said unit, and means for securing the cylinder and unit together. l

8. The combination of a combustion cylinder, an exhaust duct and an ignition device including a timer carried by said cylinder on the sides thereof, a lower unit enclosing the lower end of the cylinder reversibly mounted thereon, means thermally insulating said unit from the cylinder, means removably securing the unit to the cylinder, a piston in the cylinder and'a spring supporting said piston seated within said unit, and a charge forming device supported on said unit and communicating therethrough with the cylinder below the piston.

9. In an internal combustion hammer, the combination with a combustion cylinder, of a lower unit enclosing the lower end of the cylinder reversibly and removably mounted thereon, and a charge forming device wholly supported on said unit out of contact with the cylinder and communicating through said unit interiorly with the lower end of the cylinder for delivering combustible mixture to the cylinder without being subject to direct heat conduction therefrom.

10. The combination of a combustion cylinder, a piston reciprocable therein, aiower unit mounted on the lower end of the cylinder and removable therefrom, means for thermally insulating the unit from the cylinder, a spring confined in said unit and supporting the piston, a charge forming device supported by and communicating with said unit, and means for securing the cylinder and unit together.

11. The combination of a combustion cylinder, an exhaust duct and an ignition device including a timer ,carried by said cylinder on the sides thereof, a lower unit enclosing the lower end of the cylinder mounted thereon, means thermally insulating said unit from the cylinder,

means removably securing the unit to the cylinder, a piston in the cylinder and a spring supporting said piston seated within said unit, and a charge forming device supported on said unit and communicating therethrough with the cylinder below the piston. v"

12. In an internal combustion hammer, the combinationv with a combustionv cylinder, of a Alower unit enclosing the lower end of the cylinder detachably connected thereto and thermally insulated therefrom, and a charge forming device wholly supported on said unit out of contact with the cylinder and communicating through said unit interiorly with the lower end of the cylinder for delivering combustible mixture to the cylinder without being subject to direct heat conduction therefrom.

13. In an internal combustion hammer, a combustion cylinder, `a piston in said cylinder, a lower unit enclosing the low'rend of the cylinder detachably connected thereto and heat insulated therefrom, a fuel supply tank and carburetor wholly supported on said unit out of engagement with the cylinder communicating for delivery of fuel mixture interiorly through said unit into the bottom of said cylinder, a spring, and means supporting the same within said unit for supporting and returning said piston. v

14. In an internal combustion hammer, the combination of a cylinder, an anvil housing removably connected with the lower end of the cylinder, a piston in said cylinder, an anvil in the housing, and a spring supporting the piston upon said anvil, a tool guide s'lidably connected with said housing positioned therebelow, a handle supporting member connected with the upper end of the cylinder, an axially aligned pair of opposed handles on said member, and a pair oftenston rods connected with said member extending around the cylinder yieldably supporting said tool guide against said housing, heavy springs on said rods for supporting said tool guide, said rods lying in a plane perpendicular to the center line of said handles, said tool guide being arranged to receive impact from the anvil when the hammer is temporarily lifted from its Work.

15. In combination with a percussion hammer having a cylinder and a pair of axially aligned opposed handles secured to the upper end of the cylinder and having a yieldable impact receiving tool guide below the-cylinder supported yieldably by springs upon tension rods, the improvement which consists in providing a rigid handle supporting member at the upper end of the cylinder to which said handles are secured and securing the upper ends of said tension rods to said member aligning them so that they lie in a plane perpendicular to the axial line of said handles.

16. In an internal combustion hammer, a combustion cylinder, a piston in said cylinder, a lower unit enclosing the lower end of the cylinder detachably connected thereto and heat-insulated therefrom, a charge-forming device including a 'fuel supply tank and carburetor wholly supported on said unit out of engagement with the cylinder and having a passage for the intake of air communicating with said carburetor, a piston-return spring, and means for supporting the same within said unit.

JAMES A. MOULD. 

